Shutdown the service isolate when shutting down the VM

runtime/bin/builtin.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library builtin;
 // NOTE: Do not import 'dart:io' in builtin.
 import 'dart:async';
 import 'dart:convert';
 import 'dart:isolate';
 
@@ skipping 277 matching lines @@
   _finishedOneLoadRequest(uri);
 }
 
 
 _loadDataAsyncLoadPort(int tag,
                        String uri,
                        String libraryUri,
                        Uri resourceUri) {
   var receivePort = new ReceivePort();
   receivePort.first.then((dataOrError) {
+    receivePort.close();
     if (dataOrError is List<int>) {
       _loadScript(tag, uri, libraryUri, dataOrError);
     } else {
       assert(dataOrError is String);
       var error = new LoadError(dataOrError.toString());
       _asyncLoadError(tag, uri, libraryUri, error);
     }
   }).catchError((e) {
+    receivePort.close();
     // Wrap inside a LoadError unless we are already propagating a previously
     // seen LoadError.
     var error = (e is LoadError) ? e : new LoadError(e.toString);
     _asyncLoadError(tag, uri, libraryUri, error);
   });
 
   try {
     var msg = [receivePort.sendPort, resourceUri.toString()];
     _loadPort.send(msg);
     _startingOneLoadRequest(uri);
@@ skipping 87 matching lines @@
   } else {
     name = userUri.substring(index + 1);
     path = userUri.substring(0, index + 1);
   }
 
   path = _filePathFromUri(path);
   var filename = _platformExtensionFileName(name);
 
   return [path, filename, name];
 }